1. Technical Field
The present invention relates to an image intensifier camera, and more particularly to an x-ray image intensifier camera capable of rotating an image imaged therein.
2. Background Art
An x-ray image intensifier camera has been widely used in industrial, medical and clinical fields. Such an x-ray Image intensifier camera is an apparatus for continuously radiating x-ray beams emitted from an x-ray generator onto an object to be examined and displaying the result of the x-ray radiation on a monitor.
An x-ray image intensifier camera system comprises an x-ray generator, an image intensifier tube, and an image intensifier camera. The x-ray beams emitted from the x-ray generator are transmitted through an object to be examined, are incident onto an input window of the image intensifier tube and then are output from an output window of the image intensifier tube. The x-ray beams emitted from the output window of the image intensifier tube are imaged to produce an image in the image intensifier camera, and then the image is converted into electrical signals. The electrical signals produced in the image intensifier camera are input to an electrical signal processing unit, such as a computer, and then displayed on a monitor as an intensified fluoroscopic image.
FIG. 1 illustrates an image intensifier camera, in accordance with the conventional art.
Referring to FIG. 1, an image intensifier camera comprises a fluoroscopic image imaging optical system, an image pickup device 32, and a signal processing circuit 40 which are arranged in order from an output window 11 of an image intensifier tube. The fluoroscopic image imaging optical system includes a front lens group 21, an aperture stop 22, and a rear lens group 23. The fluoroscopic image imaging optical system further includes an output window protective window 12, placed between the output window 11 of the image intensifier tube and the front lens group 21, and an input window protective window 31, placed between the rear lens group 23 and the image pickup device 32.
To rotate a fluoroscopic image imaged in the image intensifier camera by a certain angle, the image pickup device 32 or the entire structure of the image intensifier camera should be rotated with respect to the image intensifier tube. In the case of rotating the entire structure of the image intensifier camera, the structure of the camera becomes complicated and unstable. In the case of rotating only the image pickup device 32, a disc type slip ring is required so electrical wires connected to the image pickup device 32 do not get twisted but maintain good electrical connections with the image pickup device 32. However, using a slip ring is disadvantageous in terms of low solidity and instability in electrical connections in comparison with a soldering method. Further, a slip ring is disadvantageous in that it tends to generate signal noise.